Soil sampler



Jan. 29, 1963 R. E. MITCHELL 3,075,583

SOIL SAMPLER Filed Aug. 19, 1960 IN VEN TOR.

AM, {Juan by jerking upwardly on the tube.

3,975,588 SOIL QAMPLER Robert E. Mitchell, 302 N. Main St, Lodi, Wis.Filed Aug. 19, 1968, Ser. No. 50,787 '7 Claims. (Cl. 175-420) Thisinvention relates to an improved soil sampler.

It is conventional in the construction industry to take samples ofsubsurface soil before the erection of a building thereover.Commercially available apparatus for this purpose typically consists ofa hollow tube which is driven into the ground in sections to the desireddepth. A soil sample is then admitted into the tube and the tube is thendrawn up to the surface for analysis of the entrapped sample. In allsuch prior art devices known to me, the sample is admitted into the tubeby withdrawing inwardly the point of the tube by manipulating a rod orthe like which is attached to the point and which extends through theentire length of the tube for manipulation by an operator at groundlevel. Where the tube is made in sections the rod must also be made ofsections.

In the soil sampling head of the present invention, however, all of themechanism for admitting the sample into the tube is disposed within thehead itself. Nothing need extend through the tube. Accordingly, the soilsampler of the present invention is simpler and less costly than suchprior art devices and the procedures necessary to drive the tube to thedesired depth and take the sample are speeded up.

In devices embodying the present invention a pointed end plug of thehead is subject to withdrawal inwardly under the bias of a spring. Alatch between the pointed plug and the head and engaged with ashouldered stern on the plug holds the pointed plug in place, againstthe bias of the spring, while the head is forced through the soil to thedesired depth. The latch is then released The inertia of the relativelyheavy plug and stem is such that when the tube is jerked upwardly theinertia of the plug, and stem, will hold the same against movement, thusto cause axial separation between the latch and stem shoulder. The latchis biased to retract laterally when released from engagement with thestem shoulder to a position Where it will not obstruct subsequentretracting movement of the plug and stem under bias of the spring whichwill withdraw the plug to a position where sufficient space will be leftin the end portion of the head to admit the soil sample.

Accordingly, there need be no operating mechanism between the latch andthe operator at ground-level. The latch is triggered simply by jerkingupwardly on the tube as aforesaid. The inertia of the plug and stem isrelied on for unlatching the plug.

The soil sampler head of the present invention can thus be attached toconventional soil sampling tube sections without requiring anymodification whatever therein. completely any need for extraneouscontrol mechanism between the soil sampling head and the operator.

Other objects, features and advantages of the invention will appear fromthe following disclosure in which:

FIGS. 1 and 2 are diagrammatic illustrations of soil sampling tubesequipped with a sampler head according to the present invention andshowing relative positions of the parts in the course of taking thesample.

FIG. 3 is a greatly enlarged fragmentary axial section of a soilsampling head embodying the present invention.

FIG. 4 is a similar axial cross section showing the latch in itsreleased position.

FIG. 5 is a transverse cross section taken along the line 5-5 of FIG. 3.

ttes sent Moreover, the present invention eliminates,

FIG. 6 is a transverse cross section taken along the line d-6 of FIG. 3.

As best shown in FIG. 1, soil sampling apparatus conventionallycomprises a series or string of axially jointed tubular sections ltiwhich may be coupled on mating threads 11 (FIG. 3) so that as manysections 10 may be added to the string as are needed to reach the depthof the subsurface test region. The sampling head of the presentinvention consists of a similarly elongated hollow tube 12 having athreaded coupling 11 at its upper end. At its lowermost end head 12 isprovided with a terminal hardened steel collar 13 capable ofwithstanding shocks incident to driving it through the soil.

As is conventional in this art, collar 13 is provided with an endopening 14.. A pointed plug 15 is provided which is held in its positionshown in FIG. 3 as the sampling tube is driven into the soil and whichwill be retracted to its position shown in FIG. 4 for the purpose ofadmitting into the hollow space at the end of the head 12 the coresample 16 of soil which is to be analyzed.

According to the present invention plug 15 is connec'ted. to a stem 19in any convenient manner, for example by means of a dowel 2d and setscrew 21 as shown in FIG. 3. At its end remote from the plug 15 the stem19 is provided with a cap 22 which has an axially extending aperturedear 23 providing an anchorage for one end of a tension spring 24 whichhas its other end fastened to a transverse pin 25 spanning the head tube12 near its upper end. With the plug 15 in its position shown in FIG. 3,spring 24 is tensioned and biases the plug upwardly towards a retractedposition.

Retraction of the plug is normally prevented by a latch member or arm aswhich, as best shown in FIGS. 3 and 4, desirably comprises an axiallyextending laterally biased leaf spring having an upper end portionfastened to the inner wall of the tube 12 by set screws 27. The bias ofthe spring 26 is such as to tend to move it to its position shown inFIG. 4 (and in broken lines in FIG. 3) in which the leaf spring 26 liesclosely adjacent the wall of the tube 12. However, for the purpose ofholding the plug 15 in its FIG. 3 position while the head is beingdriven into the soil, the leaf spring 26 functions as a latch and iscocked laterally against its own resilient bias and its free end engagesover the shoulder 36 on the stem 19.

To receive the free end portion of latch 2-6, the stern 3.9 is notchedout at 31. While the shoulder 3d could be formed integrally with thestem 19', it desirably consists of a wear plate 32 releasably fastenedby the screws 33 to the side of the stem 19 below the notch 31 so thatas the shoulder 3i)? wears, it may be periodically replaced. The freeend of the latch 26 is desirably notched at 34 to fit over the shoulder.

When the latch is engaged with the shoulder 36! as shown in FIG. 3, plug15 will be held against retraction upwardly, notwithstanding the bias ofthe spring 24 which tends to draw the plug into the head. Driving forceimposed on the tube string is transmitted to the plug 15 thnough thelatch 26.

To take a sample of soil in the subsurface test region indicateddiagrammatically by reference character 35 in FIGS. 1 and 2, the stringof tubes it is driven downwardly until head 12 reaches the desireddepth, which may be predetermined from previous tests. When the head 12is at the desired depth, a handle section 36 may be threaded to the topof the uppermost tube section it and a sharp blow with a hammer or thelike delivered upwardly against the handle bar 37. Accordingly, thestring of tubes It? will be jerked abruptly upwardly. The inertia of theplug 15 and stem 19- is such, however, that these parts will tend toremain at rest while the latch 3,- 3 26 which is attached to the head 12will be jerked abruptly upwardly along with the tube sections Inpractice the string of tubes is jerked upwardly a distance ofapproximately M2 or /3 inch, this being suificient to axially displacethe body 12 with respect to the plug 15 and disengage the notched end 34of the latch 26 from the shoulder B ll on the stem 19 and to permit thelateral bias of the latch spring as to snap it to its dotted lineposition shown in PEG. 3 and its full line position of FIG. 4. Tieinertia of the plug 15 and stem its"? will hold these parts in their HG.3 position only momentarily, but for a time s fficient to permitdisengagement of the latch as aforesai Thereafter, spring will be freeto draw the stem and plug upwardly to their position shown in HG. 4,thus to withdraw the plug 15 from the opening lid at the lower end ofthe head 12;. The parts are relatively dimensioned substantially asshown in the drawing to permit the stem to slide past the retractedlatch 26.

Now the string of tubes llll is driven downwardly for an additionaldist-a as, typically about one foot, as diagrammatically shown in FIG.2, thus to fill the space within the head l2 and between the plug 15 andcollar 3 with a specimen 16 of test region soil. Thereupon the entirestring of tubes is drawn upwardly to carry with it the sample 16 to thesurface, where it is removed from the head 1?, for analysis. As thestring of tubes is being withdrawn, it will ordinarily be disassembledat the joints 11.

Cup 22 is desirably notched at ed, as shown in PEG. 5, so as to it aboutthe fixed end portion of the latch 21%. Accordingly, such fixed portionof the latch will guide cap 22 for axial movement within the tubularhead 12 without rotation. The sliding engagement of the notched cap 212with the latch 25 will key the stem 15 to face its side with the notch31 and shoulder toward the latch 25.

The head E2 is desirably jointed at 41 opposite the latch 2'6.Accordingly, to reset the latch 26, the head joint 41 is opened, thestem 1% drawn axially against the bias of spring 2d, the latch 25 setagainst its shoulder 3t} and the joint it recoupled.

I claim:

1. Soil sampling apparatus comprising a tube adapted to extend fromground surface level to a subsurface soil test region, a soil samplinghead at the subsurface end of the tube, said head comprising a hollowbody having an end opening, plug means normally closing said opening andmounted for longitudinal movement in said body, spring means for biasingand plug means to a retracted position away from said opening, latchmeans comprising cooperating means on said body and said plug means forholding said plug means in said opening against the bias of said springmeans, said latch means being responsive to axial displacement of saidbody with respect to said plug means to release the plug means forprojection by the spring means to a retracted position mess in which asoil sample may be admitted into said body.

2. The device of claim 1 in which said plug means includes a stem with alatch receiving shoulder, said latch means comprising a latch mm, meansfor mounting the arm on the head with a portion thereof in abutment withthe stem shoulder, said arm resiliently biased laterally whereupon saidlatch arm will be removed from abutment with the shoulder on such axialdisplacement.

3. The device of claim 1 in which said plug means includes a stem with alatch receiving shoulder, said latch means comprising a leaf spring andmeans for mounting said spring with one end fixed with respect to thehead and its other end biased into endwise abutment against saidshoulder by said spring means, said leaf spring being biased by its ownresilience to withdraw laterally from said shoulder on relative axialdisplacement of the body with respect to said plug means and consequentseparation of the leaf spring from the shoulder to release the stem forretraction of the plug means by I said spring means from said openin 4.The device of claim 3 in which said stem is provided with a cap having anotched margin in which said leaf spring is keyed "to face the stemshoulder toward the latch.

'5. The device of claim 3 in which said stem is provided I with a latchretainer behind which a notch is formed in with an end opening, plugmeans normally closing said opening and mounted for longitudinalmovement in said body, spring means for biasing said plug means to aretracted position away from said opening, latch means comprisingcooperating means on said body and said plug means for holding said plugmeans in said opening against the bias of said spring means, said latchmeans being responsive to axial displacement of said body with respectto said plug means to release the plug means for projection by thespring means to a retracted position in which a soil sample may beadmitted into said body.

7. The device of claim 6 in which said plug means includes a stem with alatch receiving shoulder, said latch means comprising a resilientlybiased arm, means for mounting said arm on the head for movement betweenone position in which it is biased into abutment against said shoulderby said spring means, and anotherposition in which it is withdrawnlaterally from said shoulder to release the stem for retraction of theplug by said spring means from said opening.

Refierences Cited in the file of this patent UNlTED STATES PATENTSUNITED STATES PATENT OFFICE CERTIFICATE, OF CORRECTION Patent Noe3,075,588 January 29- 1963 Robert E, Mitchell It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 3, line 50, for "and" read said O Signed and sealed this 27th dayof August 1963,

(SEAL) Attest:

ERNEST w. SWIDER AVID L- LADD Attesting Officer Commissioner of Patents

1. SOIL SAMPLING APPARATUS COMPRISING A TUBE ADAPTED TO EXTEND FROMGROUND SURFACE LEVEL TO A SUBSURFACE SOIL TEST REGION, A SOIL SAMPLINGHEAD AT THE SUBSURFACE END OF THE TUBE, SAID HEAD COMPRISING A HOLLOWBODY HAVING AN END OPENING, PLUG MEANS NORMALLY CLOSING SAID OPENING ANDMOUNTED FOR LONGITUDINAL MOVEMENT IN SAID BODY, SPRING MEANS FOR BIASINGAND PLUG MEANS TO A RETRACTED POSITION AWAY FROM SAID OPENING, LATCHMEANS COMPRISING COOPERATING MEANS ON SAID BODY AND SAID PLUG MEANS FORHOLDING SAID PLUG MEANS IN SAID OPENING AGAINST THE BIAS OF SAID SPRINGMEANS, SAID LATCH MEANS BEING RESPONSIVE TO AXIAL DISPLACEMENT OF SAIDBODY WITH RESPECT TO SAID PLUG MEANS TO RELEASE THE PLUG MEANS FORPROJECTION BY THE SPRING MEANS TO A RETRACTED POSITION IN WHICH A SOILSAMPLE MAY BE ADMITTED INTO SAID BODY.